224 Theories and techniques of oral implantology

Fig. 6-33. A, This lesion may resemble leukoplakia, but upon biopsy it proved to be a squamous carcinoma. B, A neglected carcinoma at the base of the tongue in a patient with poor oral hygiene. C, The tongue should be extended to reveal as much as possible. Here the carcinoma appears as an irregular swelling. D, The ulcerated, angry-looking lesion involving the edentulous ridge and floor of the mouth is a carcinoma. E, The lesion on the undersurface of the tongue proved to be an infiltrating squamous cell carcinoma. (Courtesy Dr. Elliot W. Strong.)

Malocclusion

Abnormal occlusion may occur because of irregular positioning of the teeth alone or from abnormal positioning of the jaws. The resulting malocclusions have been divided into three categories by Stewart H. Angle.

Class I. In Class I malocclusion the jaw relationships are normal but the teeth are poorly positioned in the individual arches. Simple dental ther-

apy, such as coronal reshaping, may correct the problem and effectively restore proper centric occlusion. Once the teeth are in good occlusion and abnormal stress is reduced, the patient may be a prime candidate for an implant intervention.

Class II. In Class II malocclusion the upper posterior teeth are anterior to their opposing lowers because of a retruded position of the mandible in relation to the maxilla. Again, because good occlusion